Technical Abstract:
The study was carried out in Veracruz, Mexico in 2003 and it consisted in subjecting 27 rootstocks to four levels of drought, which were: 0 (control, with normal watering), 15, 30, and 45 days in which they were not watered. There were six replications of one plant per rootstock. The fresh and dry weight of root and canopy measured as well as leaf-area, leaf-shine, water potential, nutritional deficiency (visual) for nitrogen, iron and magnesium. The rootstocks were grouped according to the symptoms of damage presented, as follows: Group 1 (Light drought symptoms): Sacaton, Flying Dragon, Hiryu, Rubidoux, Rich-16-6, Benecke, Sunki, and Sun Chu Sha. Group 2 (Moderate drought symtoms): C-35, Depressa, Volkameriana, Carrizo, Troyer, "California" citrumelo, Rangpur, Amblycarpa, Gou Tou Cheng and Sour Orange and, Group 3 (Severe drought symptoms): Swingle, X- 639, Yuma, Taiwanica, Macrophylla, Sweet Orange, Shaub Rough lemon and Florida Rough lemon. Based on nitrogen deficiency, the rootstock most affected at 45 days of drought was Amblycarpa (6.7%). Leaf shine was gradually lost at 15, 30, and 45 days of drought. The rootstocks that showed the first symptoms of leaf curl were Florida and Shaub Rough lemons and at the end of the experiment, they were the most affected. Water potential of 14 rootstocks was greater than -5 MPa at 45 days of drought, while the Sun Chu Sha and Volkameriana, had values of -1.3 and -1.36 MPa, respectively. Leaf-area of the rootstocks at 45 days of drought was smaller compared with the control.